BOZ
Creature Cataloguer
Speed: if the faedorne and silver warrior had "120' (40')", and the shargugh has "150' (50')", if we converted the other two to 30 ft per round, why would we make the shargugh 20 ft? 
i would have their melee attack be with a silver dagger, since that is the only weapon mentioned in the entry.
i think your skill and feat selections are just fine.
Str 11 Dex 16 Con 10 Int 10 Wis 12 Cha 9 should be OK i think, as long as they don't have any abilities with Will-based saves.
Advancement by character class or by HD?
Basically the same as the dryad power, but probably a bit more powerful. Keep in mind, "individual or group", so if you have 3 shargughs in a territory, I would say the curse ability below requires the death of all 3.
Woodland Dependent (Su): Each shargugh is mystically bound to its woodland territory, which is a section of woods no larger than a 24-mile radius. A shargugh's relationship with its territory is symbiotic, and both draw strength from each other, so a shargugh must never leave its boundaries. Any shargugh who does becomes ill and dies within 1d2 days. A shargugh's woodland territory does not radiate magic.
Yeah, hallow should be fine (since druids can't cast remove curse in 3.5). should we open that up to clerics as well?
Yeah, just sounds like tree stride 5/day.
Using ye olde conversion guide for thief skill percentages (X% /5 -5), we get a Sleight of Hand and Move Silently of +12, and a Hide (in woods at least) of +13, so perhaps some racial bonuses will be in order.

i would have their melee attack be with a silver dagger, since that is the only weapon mentioned in the entry.
i think your skill and feat selections are just fine.
Str 11 Dex 16 Con 10 Int 10 Wis 12 Cha 9 should be OK i think, as long as they don't have any abilities with Will-based saves.
Advancement by character class or by HD?
DMR2 said:Each individual or group has a woodland territory roughly 24 miles in diameter. (It is exactly equal to a 24 mile wide wilderness hexagon, if these are being used.) A shargugh is tied to its territory, which nurtures its life force. In a sort of symbiosis, the woodland territory also takes strength from the shargugh, as well as being protected actively by the woodland folk. A shargugh will never voluntarily leave its territory, and if forced to do so, will sicken and die in one to two days unless returned before that time.
Basically the same as the dryad power, but probably a bit more powerful. Keep in mind, "individual or group", so if you have 3 shargughs in a territory, I would say the curse ability below requires the death of all 3.
Woodland Dependent (Su): Each shargugh is mystically bound to its woodland territory, which is a section of woods no larger than a 24-mile radius. A shargugh's relationship with its territory is symbiotic, and both draw strength from each other, so a shargugh must never leave its boundaries. Any shargugh who does becomes ill and dies within 1d2 days. A shargugh's woodland territory does not radiate magic.
DMR2 said:Any section of woodland whose shargugh is killed will become cursed and infertile for seven years. During that time, no new plants or trees will grow. Existing plants and trees will continue to grow, but will not bear any fruit or flowers. A druid who casts a remove curse spell can restore fertility to the land at any time.
Yeah, hallow should be fine (since druids can't cast remove curse in 3.5). should we open that up to clerics as well?
DMR2 said:A shargugh has the ability to transport itself instantaneously through trees for up to 600 yards. It does this by passing into one tree and emerging from another in its destination area. A shargugh can use this ability 5 times per day.
Yeah, just sounds like tree stride 5/day.
DMR2 said:Shargugh are mischievous and are likely to steal valuable objects from any creature encountering them. They are able to pick pockets with an 85% chance of success and move silently 85% of the time. To dissuade shargugh from stealing, woodland folk often leave offerings of food and drink for the creatures. In return for this, shargugh have been known to carry out small but useful tasks. They are also able to hide in woods in the same way as halflings, with a 90% chance of success.
Using ye olde conversion guide for thief skill percentages (X% /5 -5), we get a Sleight of Hand and Move Silently of +12, and a Hide (in woods at least) of +13, so perhaps some racial bonuses will be in order.